Stoneware should NEVER be put in the dishwasher. The fluctuation in temperature will cause the stone to crack. I have two customers who put old stones in the dishwasher and they shattered into tiny pieces. I have heard that stoneware can be put into the oven on a slef cleaning cycle and that will clean it. I have not tried it, but it makes sense since it was originally fired at over 2000 degrees.

I think the whole issue with the stone is to make sure at all times the whole stone is at the same temperature. I put a stone on top of my oven range one time and then turned on the wrong burner to boil water. The stone was on the burner I turned on by mistake and a few minutes later broke into 4 pieces.

I found the best thing to clean it with is baking soda and water. Make a paste with it and let it set. It prevents you from getting any yucky taste on future dishes, but it cleans it well also. I usually use it after cooking meats, especially poultry.